“In glaucoma, the increased release of glutamate is the major cause of retinal ganglion cell death. Cannabinoids have been demonstrated to protect neuron cultures from glutamate-induced death.
In this study, we test the hypothesis that glutamate causes apoptosis of retinal neurons via the excessive formation of peroxynitrite, and that the neuroprotective effect of the psychotropic Delta9-tetrahydroxycannabinol (THC) or nonpsychotropic cannabidiol (CBD) is via the attenuation of this formation.
These results suggest the potential use of CBD as a novel topical therapy for the treatment of glaucoma.
“Cannabinoid components of marijuana, such as (−)Δ9-tetrahydrocannabinol (THC), or the synthetic cannabinoid WIN55,212-2, have been shown to prevent glutamate- or NMDA-induced neurotoxicity in isolated neurons or in the brain via activation of the cannabinoid receptor subtype CB1.
…the nonpsychotropic component of marijuana, cannabidiol (CBD), and the synthetic nonpsychotropic cannabinoid, HU-211, as well as THC have been demonstrated as potent antioxidants and/or NMDA receptor antagonists that protect neuron cultures from glutamate-induced death or from oxidative stress.
… we demonstrated that THC and CBD are neuroprotective against NMDA-induced retinal injury and that their protective actions are in part because of an effect in reducing formation of lipid peroxides, nitrite/nitrate, and nitrotyrosine.
In addition to possessing neuroprotective or retinal neuroprotective activity as demonstrated here and elsewhere, cannabinoids such as THC, WIN55,212-2, endogenous cannabinoid 2-arachidonoylglycerol, as well as nonpsychotropic HU-211 have been demonstrated to induce dose-related reductions in intraocular pressure in human and in animal models.
This suggests that cannabinoids may offer a multifaceted therapy for glaucoma.
In conclusion, our results indicate that lipid peroxidation and ONOO− formation play an important role in NMDA-induced retinal neurotoxicity and cell loss in the retina, and that THC and CBD, by reducing the formation of these compounds, are effective neuroprotectants.
The present studies could form the basis for the development of new topical therapies for the treatment of glaucoma.”